import java.util.Arrays;

public class Test {
        //把数组中每个数据扩大2倍
        public static int[] func1(int[] array) {
            int[] ret = new int[array.length];
            for (int i = 0; i < array.length; i++) {
                ret[i] = array[i] * 2;
            }

            return ret;
        }
        public static void main(String[] args) {
            int[] array = {1, 2, 3, 4, 5};
            //int[] array2 =null;
            //System.out.println(array2.length);
            //System.out.println(array2[0]);
            int[] tmp = func1(array);
            System.out.println(Arrays.toString(array));
            System.out.println(Arrays.toString(tmp));
        }
    }
    //把数组中的每个数据扩大两倍--数组本身扩大2倍
    public static void func2(int[] array) {
        for (int i = 0; i < array.length; i++) {
            array[i] = array[i] * 2;

        }

    }
public static void main(String[] args) {
    int[] array = {1, 2, 3, 4, 5};
    System.out.println(Arrays.toString(array));
    func2(array);
    System.out.println(Arrays.toString(array));
}


